At 11:00 a.m. on September 10 local time, the world’s largest full-face, diameter, hard rock tunnel boring machine (TBM) “Caucasus” was put into use for the Kvesheti-Kobi highway tunnel project at an altitude of 2,000 meters through the Gudauri Mountain as part of the Greater Caucasus Mountain Range in Georgia. The TBM was jointly developed by China Railway Engineering Equipment Group and China Railway Tunnel Group, and its launch marked that this key project under the Belt and Road Initiative had entered the stage of fast construction by TBM.

With an excavation diameter of 15.08 meters, a total length of 182 meters, a weight of 3,900 tons, a maximum thrust of 22,600 tons, and a total power of 9,900 kilowatts, the “Caucasus” is so far the largest single-shield hard rock TBM in the world.

The Kvesheti-Kobi highway tunnel project as part of the North-South Road Corridor in northern Georgia, contracted by China Railway Tunnel Group, mainly consists of a 9-km-long main tunnel and an emergency tunnel. It passes through the bottom of the Gudauri ridge and will shorten the driving distance from the existing 35 kilometers on winding mountain road to 12 kilometers through straight highway, and the travel time will be reduced from one hour to 20 minutes.